The identification of gene mutations causing disease lends new insight into the pathogenesis and etiology of the disorder under examination. During the previous year we have identified mutation of ITPR1, TTBK2 and duplication of a segment on chromosome 11 as causes of spinocerebellar ataxia (SCA11, SCA15 and SCA20). We have also defined a novel locus for hereditary spastic paraplegia on chromosome 19. We have also used autozygosity mapping to define loci for varied forms of parkinsonism with and without brain iron accumulation, this includes mutation in PLA2G6, FBX07 and ATP13A2. We have also extended upon or previous identification of PRKRA mutations as a cause of parkinsonism dystonia by performing a detailed clinical investigation of the only families described thus far to contain mutations in this gene. We continue to investigate families without known mutations including rare families with parkinsonism, dystonia and ataxia, by genome wide SNP mapping and most recently by deep sequencing. We are also currently involved in a project to define mutations in Brown Vialleto Van Laere syndrome using exome sequencing.